This NSA presentation from 24 June 2009 explains how to use the email search functionality within XKeyScore: see the Intercept article XKEYSCORE: NSA’s Google for the World’s Private Communications, 1 July 2015.

This agreement, dated 15 July 1999, includes a preamble describing the development of signals intelligence cooperation between the US and Israel since the 1950s: see the Intercept article Cash, Weapons and Surveillance: the U.S. is a Key Party to Every Israeli Attack, 4 August 2014.

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1. (S) preamblei in 1968 President Johnson and Prime Minister
Eshkol agreed that an intelligence exchange would take place
between the United States and Israel. This und...